Beat egg yolks until lemon colored.Add salt and maple syrup. Cook in top of double boiler until yolk mixture thickens.Cool. Beat egg whites until stiff.Combine maple mixture,egg whites, and two third of the Kool Whip,using a folding motion.Fold in 0.75 cup of the nut meats.Scrape into baked pie shell.Cover with remaining whipped topping.Sprinkle with remaining nut meats and chocolate shavings.Freeze for a minimum of four hours.